Hearing aid technology has progressed rapidly in recent years. Technological advancements in this field continue to improve the reception, wearing-comfort, life-span, and power efficiency of hearing aids. With these continual advances in the performance of ear-worn acoustic devices, ever-increasing demands are placed upon improving the inherent performance of the miniature acoustic transducers that are utilized. There are several different hearing aid styles including: Behind-The-Ear (BTE), In-The-Ear or All In-The-Ear (ITE), In-The-Canal (ITC), and Completely-In-The-Canal (CTC).
Generally, a listening device, such as a hearing aid, includes a microphone assembly, an amplifier and a receiver (speaker) assembly. The microphone assembly receives vibration energy, i.e. acoustic sound waves in audible frequencies, and generates an electronic signal representative of these sound waves. The amplifier accepts the electronic signal, modifies the electronic signal, and communicates the modified electronic signal (e.g., processed signal) to the receiver assembly. The receiver assembly, in turn, converts the increased electronic signal into vibration energy for transmission to a user.
Conventionally, the receiver assembly utilizes moving parts (e.g., armature, diaphragm, etc.) to generate acoustic energy in the ear canal of the hearing aid wearer. If the receiver assembly is in contact with another hearing aid component, the momentum of these moving parts will be transferred from the receiver assembly to the component and from the component back to the microphone assembly. This transferred momentum or energy may then cause unintended electrical output from the microphone, i.e., feedback. This mechanism of unwanted feedback limits the amount of amplification that can be applied to the electric signal representing the received sound waves. In many situations, this limitation is detrimental to the performance of the hearing aid. Consequently, it is desirable to reduce the vibration and/or magnetic feedback that occurs in the receiver assembly of the hearing aid or other similar devices.